When three year-old Madeleine McCann went missing from a Portuguese holiday resort in 2007, it was a story which had the nation gripped for all the wrong reasons. 18 years on, the case remains unsolved - but the story still has the power to create headlines and dominate the news agenda.

In this episode, Andy and Neil look at the key mistakes that were made early in the investigation by the local police - and whether there is a realistic chance of this case ever being solved.

Neil also reveals how high profile murder and missing persons investigations are carried out in the UK, and why some 'cold cases' - such as the Stephen Lawrence murder - can eventually be solved many years later.

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